OpenSSL::PKey::EC::Group#point_conversion_form

static VALUE ossl_ec_group_get_point_conversion_form(VALUE self)
{
    EC_GROUP *group;
    point_conversion_form_t form;

    GetECGroup(self, group);
    form = EC_GROUP_get_point_conversion_form(group);

    switch (form) {
      case POINT_CONVERSION_UNCOMPRESSED:
        return sym_uncompressed;
      case POINT_CONVERSION_COMPRESSED:
        return sym_compressed;
      case POINT_CONVERSION_HYBRID:
        return sym_hybrid;
      default:
        ossl_raise(eEC_GROUP, "unsupported point conversion form: %d, " \
                   "this module should be updated", form);
    }
}